Rapid Responses to:

MINERVA: Minerva BMJ 2000; 321: 1166 [Full text]

Rapid Responses: Submit a response to this article

Rapid Responses published:

Long haul flights

A C McEwan   (6 November 2000)

Mexican Red Kneed Spiders

David Laws   (7 November 2000)

Flying might be associated with blood clots

Christopher Cates   (14 November 2000)

Re. Mexican Red-Kneed Spiders

Yvonne Wraige   (10 January 2001)

Long haul flights 6 November 2000
A C McEwan, Scientific Director National Radiation Laboratory Send response to journal: Re: Long haul flights	Minerva in discussing a recent study on the link between travel and deep vein thrombosis (Lancet 2000;356:1492)indicates no association was found even for long flights. Long flights were specified as greater than 5 hours. This seems to be a European view of a "long flight". I have made may trips to Vienna from Christchurch through London. These have a total travel time one way of about 32 hours, with about 28 of these spent sitting in aircraft. The longest single hop is about 14 hours. Perhaps a study should be done on travellers to Europe from the Antipodes.
Mexican Red Kneed Spiders 7 November 2000
David Laws, Consultant Ophthalmologist Singleton Hospital, Swansea Send response to journal: Re: Mexican Red Kneed Spiders	Editor The use of behavioural therapy to deal with some of the fears of people faced with progressive immobility was well illustrated by Leigh et al. They showed a photograph of a woman with motor neurone disease holding a Mexican red kneed spider so that she would learn to cope if unable to escape from an approaching arachnid. While the principle of this form of therapy is very reasonable the use of this particular species may have unforseen consequences. Brachypelma smithii has an unusual defence mechanism. When stressed, as may occur during this type of therapy, the spider rubs its legs against its abdomen releasing a shower of fine hairs. These are barbed and if they come into contact with the ocular surface will penetrate causing inflammation. Lesions have been reported in all layers of the globe. Apart from damage to the eyes this would not do much to allay the fear of spiders. 1. Parton M. Leigh PN. Whittaker M. Marks I. Minerva. BMJ 2000;321:1166 (4 November) 2. Watts P. Mcpherson R. Hawksworth NR. Tarantula keratouveitis. Cornea. 19(3):393-4, 2000 May 3. Shrum KR. Robertson DM. Baratz KH. Casperson TJ. Rostvold JA. Keratitis and retinitis secondary to tarantula hair. Archives of Ophthalmology. 117(8):1096-7, 1999 Aug. David Laws Consultant Ophthalmologist Singleton Hospital, Swansea SA2 8QA UK david.laws@lineone.net
Flying might be associated with blood clots 14 November 2000
Christopher Cates, General Practitioner Bushey, Hertfordshire Send response to journal: Re: Flying might be associated with blood clots	EDITOR - Minerva suggests that readers may find the Lancet research letter reassuring with respect to the risks of flying and deep vein thrombosis. I cannot share this view as the study design is unable to assess any increased risk of DVT unless it is known whether there is a corresponding rise in swollen legs that do not contain a clot. If flying caused an increase of, say, tenfold in both types of leg problem, then the Odds Ratio would still be 1.0. Since it is not uncommon for people who fly to develop some leg swelling the study cannot inform us whether DVT and flying are associated or not. The more correct conclusion is that a clinically suspicious swollen leg after flying has a similar likelihood of testing positive for DVT on venogram or ultrasound as a leg of the same appearance in a non-flyer.
Re. Mexican Red-Kneed Spiders 10 January 2001
Yvonne Wraige, Retired Send response to journal: Re: Re. Mexican Red-Kneed Spiders	Editor, It was interesting to read Mr Laws' comments about the hazards associated with Mexican Red-Kneed Spiders like the one pictured in my hands. Happily, no problems resulted during my time with Gina. She is one of several at London Zoo that are used to being handled. I believe females are preferred for this purpose as they are more content to just sit. While at the zoo, I held 3 female Mexican Red-Kneed spiders, picking them up myself. If I had been at all anxious I would not have been able to do this. The visit to the zoo took place after my behavioural therapy sessions with British spiders had finished and my fear of spiders had disappeared. Yours, Yvonne Wraige PS I have no wish to remain anonymous